Vernon

Vernon is a doctor and cancer survivor. He is first introduced as Lee escapes the sewers during Episode 4. When he first met Lee he thought he was a member of Crawford. Lee, upon learning Vernon was a doctor, asked him if he could come with him to help Omid.

He along with Lee, Brie, and the rest of Lee's group (Clementine can come with you or stay in the house if you decide) infiltrated Crawford mid-way in Episode 4 to get the necessary supplies to get the boat up and running.

At the beginning of Episode 5, he alongside the other cancer survivors that we're with him, stole the boat Lee and his group we're going to use to escape. He and the other cancer survivors locked Lee's group in the garage (or left a note if everyone came with you to get Clementine) where the boat was while Lee was looking for Clementine.